The present invention pertains to a step which is movably supported relative to a selected side of an automotive vehicle such as a camper, van, and other similar types of vehicles in which the bottom of the door opening of the cab or body is substantially higher than the sill of a normal passenger-type automobile, whereby it is difficult for many types of persons to readily step from the ground or roadway into the door opening. Auxiliary or supplemental types of steps for this type of vehicle have been devised heretofore. One example of such prior steps is illustrated in U.S. Pat. No. 3,329,443 to Lowder et al, dated July 4, 1976, and in which a step is simply pivotally supported by an L-shaped arm that is manually movable between an extended and a retracted position, the step being held selectively in said alternate positions by spring actuated detents engaging suitable stop members on a bracket which supports the L-shaped arm.
A further type of auxiliary step which is power-operated is illustrated in U.S. Pat. No. 3,762,742 to Bucklen, dated Oct. 2, 1973. A pivoted arm is moved between extended and retracted positions by an electric motor which operates a screw which extends through a pivotally mounted nut member interconnected to the arm of the step for purposes of moving it respectively in opposite directions as aforesaid, depending upon the direction in which the screw is rotated.
Still another type of auxiliary step comprises the subject matter of later U.S. Pat. No. 4,073,502 to Frank et el, dated Feb. 14, 1978, and in which a horizontal step is supported by two sets of parallel arms which depend from a bracket secured to the side of a van or the like, adjacent the sill of a door, a vacuum unit being employed normally to maintain the step in retracted position, and spring means move the step to extended position, whereby when the engine of the vehicle is not running, there is no vacuum to maintain the step in retracted position and said springs automatically move the step to extended or operative position.
The purpose of the present invention is to provide improvements over said prior devices, particularly to render the same safe in operation and for other purposes set forth hereinbelow.